To add a bit to what Jon just posted, you also need to make sure you have clearance room for the MTx190 needle in the needle plate and anything under it. The MTx190s being round will sit a wee bit to the left of where the Davis Long would sit.
In my Minnesota ~B~ I bought one size at a time trying each to make sure. I can use the MTx190s up to size 18. I doubt I could go any larger though.
Joe